PSI - Issue 64

Donatella de Silva et al. / Procedia Structural Integrity 64 (2024) 1806–1814 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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b=1.73 a=0.00 β (DCR|IM) = 0.78

PL III Res

PL IV

Figure 7. Linear regression for peak heat release rate

where: a it’s the regression intercept; b is slope coefficient on the line regression; β is the standard deviation; the blue line represents the line regression; the red vertical line represents unitary DCR; each blue point represents a fire scenario characterized by a certain DCR value and certain IM value. Similarly, in the Figure 8, linear regression are reported for the prestressed reinforced concrete bridge in the case where the chosen measure of intensity to characterize the fire is the fire load.

b=0.52 a=0.08 β (DCR|IM) =0.18 b=1.50 a=0.00 β (DCR|IM) = 0.86

PL III

PL IV Res

b=1.52 a=0.00 β (DCR|IM) = 0.91

PL III Res

PL IV

Figure 8. Linear regression for the fire load

The curves show in Figure 9 and in Figure 10 display the fragility curves obtained for both types of analyzed structures. These curves have been determined for both performance level III and performance level IV, considering both the fire load and the peak thermal release rate, and finally accounting for both maximum displacement and residual displacement as response parameters of the structures.